The present invention relates generally to a device and method for removing lining material from the adhesive surface such as a pressure sensitive adhesive surface of an article. More specifically, the present invention is a device and method for obtaining a bend tab to facilitate the separation of the liner from the pressure sensitive adhesive surface of an article.
Those skilled in the art of separating lining material from the pressure sensitive adhesive surface of articles are aware of basic problems such as loss of tear-off tab members, nonrelease from the adhesive surface which results in damaged articles, tearing of the lining material which requires either considerable time consuming efforts to release the balance of the lining material, or rejection of the article. It is generally known to flex an article to release the lining material from the pressure sensitive adhesive surface, but such generalized flexing is inefficient and often ineffective for the complete separation of the lining material from the adhesive surface.
Other inefficient techniques used in the industry include a "kiss-cut," i.e., the article is cut but not the release liner. There are at least three modes for failure with such a technique: A. the article is not cut through one hundred percent (100%); B. the cut often penetrates both the article and a portion of the liner; and C. the liner is cut in a manner which destroys the tab. This technique often requires more expensive material to allow a larger margin for error. Such problems are costly in both labor and materials. Loss of tab members not only causes an additional disposal problem, the tabs can cause problems with subsequent machinery and operations.
Another attempt to solve the problem of efficiently separating the release liner from the pressure sensitive adhesive surface includes indenting a segment of the edge of the article and attaching another material to the release liner to bridge the gap caused by such indentation. There are at least two modes of failure inherent in this operation: A: the bridge tab applied is expensive and often pops off the release liner; and B. there is often a cohesive failure when the article consists of weaker materials, e.g. felts, roofing paper, and the like., and when the bridge tab is pulled to initiate the release of the liner, the forces required for such removal are concentrated in the areas of indentation adjacent the perimeter of the article, and this causes a failure because of the weak material, i.e., the material fails cohesively instead of initiating the release of the liner. Generally, when such "bridge" material fails to initiate the release of the liner material from the article, this destroys the article.
Currently available devices and methods for separating lining material from a pressure sensitive adhesive surface of an article includes a tear-off tab member which has a minimum land area and a narrow tab area which renders them too weak to be efficient and often causes cohesive failure of the article. Other methods of liner removal include an extension of a portion of the lining material beyond an edge of the article, and, in some applications, the adhesive material is not extended to the perimeter of the article. Other technology includes embrittling a portion of the release liner so that the liner breaks to form a released portion for grasping. Each of these methods requires the use of extra material as well as extra processing, and they are neither as efficient, effective nor as economical as is the device and method of the present invention.
The state of the art, thus far, does not provide an efficient, cost effective device and method for separating a lining material from the pressure sensitive adhesive surface of an article. The built-in waste factor from the presently available articles which have lining material applied to the pressure sensitive adhesive surface of the article, can adversely affect the economics of the application operation for such an article in industry. The time required for finding an alternate release segment when a tab member is lost, as well as the cost of rejecting articles rendered defective by the non-efficient separation of the lining material from the pressure sensitive adhesive surface, or cohesive failure of the article, adversely affect the economics of the currently available tab release methods.